Emergence of Streptococcus pyogenes emm102 Causing Toxic Shock Syndrome in Southern Taiwan during 2005–2012

Jiun-Nong Lin,Lin-Li Chang,Hsi-Hsun Lin,Yen-Hsu Chen,Chung-Hsu Lai,Herminia De Lencastre

doi:10.1371/journal.pone.0081700

Abstract

BackgroundStreptococcal toxic shock syndrome (STSS) is an uncommon but life-threatening disease caused by Streptococcus pyogenes.MethodsTo understand the clinical and molecular characteristics of STSS, we analyzed clinical data and explored the emm types, superantigen genes, and pulsed-field gel electrophoresis of causative S. pyogenes isolates obtained between 2005 and 2012.ResultsIn total, 53 patients with STSS were included in this study. The median age of the patients was 57 years (range: 9–83 years), and 81.1% were male. The most prevalent underlying disease was diabetes mellitus (45.3%). Skin and soft-tissue infection accounted for 86.8% of STSS. The overall mortality rate was 32.1%. Underlying diseases had no statistical impact on mortality. A total of 19 different emm types were identified. The most prevalent emm type was emm102 (18.9%), followed by emm11 (17%), emm1 (11.3%), emm87 (9.4%), and emm89 (7.5%). There was no statistically significant association between emm type and a fatal outcome. Among the superantigen genes, speB was the most frequently detected one (92.5%), followed by smeZ (90.6%), speG (81.1%), speC (39.6%), and speF (39.6%). The majority of emm102 strains were found to have speB, speC, speG, and smeZ. The presence of speG was negatively associated with a fatal outcome (P = 0.045).ConclusionsOur surveillance revealed the emergence of uncommon emm types, particularly emm102, causing STSS in southern Taiwan. Characterization of clinical, epidemiological, and molecular characteristics of STSS will improve our understanding of this life-threatening disease.

Highlights

Streptococcal toxic shock syndrome (STSS) is a rare but potentially fatal disease that is characterized by the sudden onset of shock and multiple organ failure [1]
This reaction results in T cell proliferation and produces massive amounts of cytokines that lead to rash, fever, capillary leakage, organ failure, and subsequent shock [2,6,7]
Demographic Data During the study period, 53 patients were diagnosed with STSS

Summary

Introduction

Streptococcal toxic shock syndrome (STSS) is a rare but potentially fatal disease that is characterized by the sudden onset of shock and multiple organ failure [1]. It is caused by toxinproducing strains of Streptococcus pyogenes (group A streptococcus [GAS]) [2] This microorganism exists ubiquitously in the environment and can cause a wide variety of human infections that range from mild pharyngitis and cellulitis to life-threatening diseases, such as necrotizing fasciitis, puerperal sepsis, pneumonia, bacteremia, and STSS [3]. SAgs can bypass the conventional process of antigen presentation and interact with antigen-presenting cells and T cells simultaneously This reaction results in T cell proliferation and produces massive amounts of cytokines that lead to rash, fever, capillary leakage, organ failure, and subsequent shock [2,6,7]. Allelic variations were found in SAg genes, including speA, speC, speG, ssa, and smeZ [12,13,14,15]. Streptococcal toxic shock syndrome (STSS) is an uncommon but life-threatening disease caused by Streptococcus pyogenes

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Conclusion